Heat treatment apparatus and temperature control method

ABSTRACT

There is provided a heat treatment apparatus for performing a predetermined film forming process on a substrate by mounting the substrate on a surface of a rotary table installed in a processing vessel and heating the substrate by a heating part while rotating the rotary table. The heat treatment apparatus includes: a first temperature measuring part of a contact-type configured to measure a temperature of the heating part; a second temperature measuring part of a non-contact type configured to measure a temperature of the substrate mounted on the rotary table in a state where the rotary table is being rotated; and a temperature control part configured to control the heating part based on a first measurement value measured by the first temperature measuring part and a second measurement value measured by the second temperature measuring part.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Japanese Patent Application No.2015-130165, filed on Jun. 29, 2015, in the Japan Patent Office, thedisclosure of which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

The present disclosure relates to a heat treatment apparatus and atemperature control method.

BACKGROUND

A heat treatment apparatus in which semiconductor wafers (hereinafter,referred to as “wafers”) as a plurality of substrates are mounted on arotary table in a rotational direction of the rotary table installedinside a processing vessel has been used. This heat treatment apparatusincludes a gas supply part installed in the diameter direction of therotary table to supply a processing gas and a heater installed below therotary table to heat the wafers. In addition, the rotary table isrotated in a state where the gas is discharged from the gas supply partand the wafers are heated by the heater, so that each of the wafers issubjected to a film forming process.

In such a heat treatment apparatus, for example, a temperature controlis performed using, as a wafer temperature, a temperature measured by athermocouple (TC for heater control) installed near the heater.

A semiconductor manufacturing apparatus has also been used in which atemperature of a susceptor having wafers mounted thereon is measuredusing a radiation thermometer in a film forming process, and an outputof a heater is controlled based on the measurement result, therebyperforming the film forming process on the wafers.

However, the apparatus fails to accurately measure a temperature of thewafer in the film forming process which is performed while rotating therotary table. This makes it difficult to perform the film formingprocess on the wafer by controlling the wafer to have an appropriatetemperature.

SUMMARY

In some embodiments of the present disclosure, a heat treatmentapparatus includes a rotary table having substrates mounted thereon androtating inside a processing vessel, and can accurately controltemperatures of the substrates.

According to one embodiment of the present disclosure, there is provideda heat treatment apparatus for performing a predetermined film formingprocess on a substrate by mounting the substrate on a surface of arotary table installed in a processing vessel and heating the substrateby a heating part while rotating the rotary table, the heat treatmentapparatus including: a first temperature measuring part of acontact-type configured to measure a temperature of the heating part; asecond temperature measuring part of a non-contact type configured tomeasure a temperature of the substrate mounted on the rotary table in astate where the rotary table is being rotated; and a temperature controlpart configured to control the heating part based on a first measurementvalue measured by the first temperature measuring part and a secondmeasurement value measured by the second temperature measuring part.

According to another embodiment of the present disclosure, there isprovided a temperature control method used in a heat treatment apparatusfor performing a predetermined film forming process on a substrate bymounting the substrate on a surface of a rotary table installed inside aprocessing vessel and heating the substrate by a heating part whilerotating the rotary table, the temperature control method including:mounting the substrate on the rotary table; measuring, by a firsttemperature measuring part of a contact-type, a temperature of theheating part; measuring, by a second temperature measuring part of anon-contact type, a temperature of the substrate mounted on the rotarytable in a state where the rotary table is being rotated; andcontrolling the heating part based on a first measurement value measuredby the first temperature measuring part and a second measurement valuemeasured by the second temperature measuring part.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the presentdisclosure, and together with the general description given above andthe detailed description of the embodiments given below, serve toexplain the principles of the present disclosure.

FIG. 1 is a schematic longitudinal cross sectional view of a heattreatment apparatus according to an embodiment of the presentdisclosure.

FIG. 2 is a schematic perspective view of the heat treatment apparatusaccording to the embodiment of the present disclosure.

FIG. 3 is a schematic plan view of the heat treatment apparatusaccording to the embodiment of the present disclosure.

FIG. 4 is a partial cross sectional view illustrating a temperaturemeasuring part in the heat treatment apparatus according to theembodiment of the present disclosure.

FIGS. 5A to 5C are views illustrating an operation of a radiationtemperature measuring part.

FIG. 6 is a view illustrating a relationship between a rotary table anda temperature measurement region.

FIG. 7 is a table illustrating a correlation between a heaterthermocouple and the radiation temperature measuring part.

FIGS. 8A and 8B are views illustrating temperature distributions of awafer in states where the rotary table is being rotated and the rotarytable is not being rotated.

FIG. 9 is a view illustrating positions of wafers mounted on the rotarytable.

FIGS. 10A and 10B are views illustrating effects of the heat treatmentapparatus according to the embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments, examples ofwhich are illustrated in the accompanying drawings. In the specificationand drawings, like reference numerals will be assigned to like partshaving substantially the same functions and duplicate descriptionsthereof will be omitted. In the following detailed description, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present disclosure. However, it will be apparent toone of ordinary skill in the art that the present disclosure may bepracticed without these specific details. In other instances, well-knownmethods, procedures, systems, and components have not been described indetail so as not to unnecessarily obscure aspects of the variousembodiments.

<Configuration of Heat Treatment Apparatus>

An example of a heat treatment apparatus according to an embodiment ofthe present disclosure will now be described. FIG. 1 is a schematiclongitudinal cross sectional view of the heat treatment apparatusaccording to this embodiment FIG. 2 is a schematic perspective view ofthe heat treatment apparatus according to the embodiment. FIG. 3 is aschematic plan view of the heat treatment apparatus according to theembodiment.

The heat treatment apparatus 1 of the embodiment includes a flatprocessing vessel 11 of a substantially circular shape and a disk-likerotary table 12 horizontally installed inside the processing vessel 11.The processing vessel 11 is installed in an atmospheric environment, andincludes a ceiling plate 13 and a vessel main body 14 constituting asidewall 14 a and a bottom portion 14 b of the processing vessel 11. InFIG. 1, a reference numeral 11 a designates a sealing member forair-tightly maintaining the interior of the processing vessel 11, and areference numeral 14 c designates a cover for blocking a central portionof the vessel main body 14. In FIG. 1, a reference numeral 12 a is arotary drive mechanism which rotates the rotary table 12 in acircumferential direction. Also, the rotary drive mechanism 12 a inputsa signal related to a rotational position or rotational speed of therotary table 12 to a temperature control part 5 which will be describedlater.

Five concave portions 16 are formed in a surface of the rotary table 12along a rotational direction of the rotary table 12. In FIG. 2,reference numeral 17 designates a transfer port. In FIG. 3, referencenumeral 18 designates a shutter (not shown in FIG. 2) capable ofopening/closing the transfer port 17. If a transfer mechanism 2A entersinto the processing vessel 11 through the transfer port 17 while holdinga wafer W, lifting pins (not shown) protrude upward from the rotarytable 12 through holes 16 a formed in the concave portion 16 at aposition facing the transfer port 17 such that a wafer W is raised. Inthis way, the wafer W is transferred between the concave portion 16 andthe transfer mechanism 2A.

A series of operations performed by the transfer mechanism 2A, thelifting pins, and the rotary table 12 is repeated, so that wafers W aretransferred into the respective concave portions 16. Unloading of thewafer W from the processing vessel 11 is performed by raising the waferW received in the concave portion 16 using the lifting pins, and pickingup the wafer W by the transfer mechanism 2A.

A first reaction gas nozzle 21, a separation gas nozzle 22, a secondreaction gas nozzle 23, and a separation gas nozzle 24, which extend ina rod shape toward the center from an outer periphery of the rotarytable 12, are sequentially arranged above the rotary table 12 in acircumferential direction. Each of the gas nozzles 21 to 24 includesopenings formed at a lower portion thereof to supply a gas along thediameter of the rotary table 12. The first reaction gas nozzle 21discharges a BTBAS (bis-tertiary-butyl-amino-silane) gas and the secondreaction gas nozzle 23 discharges an O₃ (ozone) gas, respectively. Theseparation gas nozzles 22 and 24 discharge an N₂ (nitrogen) gas,respectively.

The ceiling plate 13 of the processing vessel 11 includes two fan-likeprotruding portions 25 protruding downward. The protruding portions 25are formed in a mutually spaced-apart relationship along thecircumferential direction. Each of the separation gas nozzles 22 and 24is installed to be embedded into the respective protruding portion 25 sothat the respective protruding portion 25 is divided in thecircumferential direction. The first reaction gas nozzle 21 and thesecond reaction gas nozzle 23 are installed to be spaced apart from eachother in the respective protruding portions 25.

A heater 20 is installed under the rotary table 12. The heater 20 is anexample of a heating part for heating the wafers W mounted on the rotarytable 12. Specifically, the heater 20 is concentrically arranged arounda rotational center P of the rotary table 12. An example of the heater20 may include a resistance heater or an induction heater, such as ametal wire heater, a molybdenum heater or a carbon wire heater.

A heating region of the processing vessel 11 is partitioned into aplurality of (three in FIG. 1) zones Za, Zb, and Zc so as to control atemperature in the diameter direction of the rotary table 12. Inaddition, the heater 20 is configured by three zone heating heaters 20a, 20 b and 20 c which are divided corresponding to the respective zonesZa, Zb, and Zc, so that the zone heating heaters 20 a, 20 b, and 20 ccan be individually controlled. The number of zones is not particularlylimited, and may be one, two, or four or more.

Three heater thermocouples 3 a, 3 b, and 3 c for measuring temperaturesof the zone heating heaters 20 a, 20 b, and 20 c are installed near thezone heating heaters 20 a, 20 b, and 20 c, respectively. Hereinafter,the three heater thermocouples 3 a, 3 b, and 3 c are sometimes simplyreferred to as a heater thermocouple 3.

The heater thermocouple 3 is an example of a contact-type firsttemperature measuring means for measuring a temperature of the heater20. Specifically, one end of each of the heater thermocouples 3 a, 3 b,and 3 c air-tightly penetrates through the bottom portion 14 b of thevessel main body 14 from below the vessel main body 14 and is disposedunder the rotary table 12. Meanwhile, the other end of each of theheater thermocouples 3 a, 3 b, and 3 c is connected to the temperaturecontrol part 5 (to be described later). A measurement value (a firstmeasurement value) obtained at each of the heater thermocouples 3 a, 3b, and 3 c is inputted to the temperature control pail 5 equipped with,e.g., a microcomputer or the like. In addition, based on the measurementvalues, the heating part s controlled and wafers W mounted on the rotarytable 12 are heated.

If the wafers W are mounted in the respective concave portions 16, theinterior of the processing vessel 11 is exhausted through exhaust port26 which is formed outside the rotary table 12 in the diameter directionof the rotary table 12 from a region between separation regions D1 andD2 under the protruding portions 25 in the bottom of the vessel mainbody 14, so that the interior of the processing vessel 11 becomes avacuum atmosphere. In addition, the rotary table 12 is rotated andsimultaneously, the wafer W is heated to a predetermined temperaturethrough the rotary table 12 by the heater 20 installed below the rotarytable 12. In FIG. 3, an arrow 27 indicates a rotational direction of therotary table 12.

Subsequently, gases are supplied from the respective gas nozzles 21 to24, and the wafer W alternately passes through a first processing regionP1 under the first reaction gas nozzle 21 and a second processing regionP2 under the second reaction gas nozzle 23. Accordingly, the BTBAS gasis adsorbed onto the wafer W, and the O₃ gas is subsequently adsorbedonto the wafer W, so that BTBAS molecules are oxidized. Thus, amolecular layer of silicon oxide is formed in a single layer or plurallayers. In this way, the molecular layers of silicon oxide aresequentially stacked, thereby forming a silicon oxide film having apredetermined film thickness.

The N₂ gas supplied to the separation regions D1 and D2 from theseparation gas nozzles 22 and 24 in the film forming process spreads inthe circumferential direction in the separation regions D1 and D2, toprevent the BTBAS gas and the O₃ gas from being mixed together on therotary table 12. In addition, surplus BTBAS gas and O₃ gas are flowedinto the exhaust ports 26. Furthermore, in the film forming process, theN₂ gas is supplied into a space 28 defined in a central region C of therotary table 12. In the ceiling plate 13, the N₂ gas passes throughbelow a ring-shaped protruding portion 29 formed to protrude downwardand flows toward the outside in the diameter direction of the rotarytable, thereby preventing the BTBAS gas and the O₃ gas from being mixedtogether in the central region C. In FIG. 3, flows of the respectivegases in the film forming process are shown by arrows. Although notshown in this figure, the N₂ gas is also supplied into the cover 14c andonto a back side of the rotary table 12, so that the reaction gases arepurged.

Next, the heat treatment apparatus 1 according to the embodiment will bedescribed also with reference to FIG. 4 which shows an enlargedlongitudinal cross section of the ceiling plate 13 and the rotary table12. FIG. 4 is a partial cross sectional view illustrating the radiationtemperature measuring part 4 in the heat treatment apparatus 1 accordingto this embodiment. Specifically, FIG. 4 shows across section betweenthe processing region P1 in which the first reaction gas nozzle 21 isinstalled and the separation region D2 defined adjacent to an upstreamside of the processing region P1 in the rotational direction of therotary table 12.

In the ceiling plate 13, a slit 41 extending in the diameter directionof the rotary table 12 is formed at a position indicated by a dasheddotted line in FIG. 3. A lower window 42 and an upper window 43 areinstalled to respectively cover top and bottom portions of the slit 41.The lower window 42 and the upper window 43 are made of, for example,sapphire to allow infrared ray radiated from a front side of the rotarytable 12 to transmit through the lower and upper windows 42 and 43.Thus, the radiation temperature measuring part 4 (to be described later)can measure a radiation temperature of the infrared ray. The term “frontside” of the rotary table 12 used herein includes a front side of thewafer W.

The radiation temperature measuring part 4 is installed above the slit41. The radiation temperature measuring part 4 is an example of anon-contact type second temperature measuring means that measurestemperatures of wafers W mounted on the rotary table 12 while the rotarytable 12 is rotated.

FIG. 4, the height H from the surface of the rotary table 12 to a bottomend of the radiation temperature measuring part 4 is, for example, 500mm. The radiation temperature measuring part 4 induces the infrared rayradiated from a temperature measurement region of the rotary table 12 toa detection part 401 (to be described later) so that the detection part401 acquires a measurement value (second measurement value)corresponding to an amount of the infrared ray. As such, the measurementvalue varies depending on a temperature of an acquirement place. Theacquired measurement value is transmitted to the temperature controlpart 5 which will be described later.

Next, an operation of the radiation temperature measuring part 4 will bedescribed with reference to FIGS. 5A to 5C. FIGS. 5A to 5C are viewsillustrating an operation of the radiation temperature measuring part 4.

As shown in FIGS. 5A to 5C, the radiation temperature measuring part 4includes a rotational body 402 equipped with a servomotor that rotatesat 50 Hz. The rotational body 402 is configured in a triangular shapewhen viewed from the top. Three side surfaces of the rotational body 402are defined as reflective surfaces 403 to 405. As shown in FIGS. 5A to5C, as the rotational body 402 rotates around a rotating shaft 406, theinfrared ray radiated from a temperature measurement region 410 in therotary table 12 having the wafer W mounted thereon is reflected at anyone of the reflective surfaces 403 to 405 as indicated by an arrow inFIGS. 5A to 5C. This reflected infrared ray is induced to the detectionpart 401. In addition, scanning is performed while moving a position ofthe temperature measurement region 410 in the diameter direction of therotary table 12.

The detection part 401 is configured to continuously acquire theinfrared ray a predetermined number of times (e.g., 128 times) from therespective reflective surface, to detect temperatures at predeterminedplaces e.g., 128 places) in the diameter direction of the rotary table12. In addition, the reflective surfaces 403 to 405 are sequentiallylocated on an optical path of the infrared ray with the rotation of therotational body 402, so that the scanning can be repeatedly performedtoward the outside from the inside of the rotary table 12. Here, thespeed of the scanning is 150 Hz. That is to say, the radiationtemperature measuring part 4 can perform the scanning 150 times for onesecond. The temperature measurement region 410 is a spot having adiameter of 5 mm. The scanning is performed in a section ranging frominward of the concave portion 16 into which the wafer W is mounted inthe rotary table 12 to an outer peripheral end of the rotary table 12.In FIG. 4, dashed dotted lines 44 and 45 indicate paths of the infraredray that orients to the radiation temperature measuring part 4 from thetemperature measurement regions 410 when the temperature measurementregions 410 moves to the innermost and outermost peripheral sides of therotary table 12.

The scanning by the radiation temperature measuring part 4 is performedin a state where the rotary table 12 is rotated. The rotational speed ofthe rotary table 12 is 240 rpm in this embodiment FIG. 6 is a plan viewillustrating a relationship between the rotary table 12 and thetemperature measurement region 410. In FIG. 6, reference numeral 411designates a row (scan line) of the temperature measurement region 410when an nth (n is an integer) scanning is performed outward from inwardof the rotary table 12 in a state where the rotary table 12 is rotated.In FIG. 6, reference numeral 412 designates a scan line when an (n+1)th(n is an integer) scanning is performed. With the rotation of the rotarytable 12, a central angle between the scan lines 411 and 412 withrespect to the rotational center P of the rotary table 12 is offset byan angle θ1 corresponding to the rotational speed of the rotary table12. By repeating the scanning while rotating the rotary table 12 asdescribed above, measurement values at a plurality of positions on therotary table 12 are sequentially acquired.

The temperature control part 5 controls a heater driving part 6 tocontrol the temperature of the wafer W, based on the measurement valuesmeasured by the heater thermocouple 3 and the measurement valuesmeasured by the radiation temperature measuring part 4. In addition,signals related to the rotational position and the rotational speed ofthe rotary table 12 are inputted to the temperature control part 5 fromthe rotary drive mechanism 12 a.

In FIG. 1, a storage part 7 is a memory storing a table or the like,which will be described later.

<Temperature Control Method>

Next, an example of a temperature control method performed using theaforementioned heat treatment apparatus 1 of the embodiment will bedescribed.

First, a film forming process performed on a product wafer using theheat treatment apparatus 1 will be described.

The shutter 18 installed in the transfer port 17 is opened, and theproduct wafer is transferred into the concave portion 16 of the rotarytable 12 from outside of the processing vessel 11 through the transferport 17 by the transfer mechanism 2A. Such a transfer operation isperformed by raising and lowering the lifting pins (not shown) throughthrough-holes formed in the bottom surface of the concave portion 16from a lower portion of the processing vessel 11 when the concaveportion 16 is positioned at a position facing the transfer port 17. Thetransfer operation of the product wafer is performed by intermittentlyrotating the rotary table 12, so that product wafers are mounted in thefive concave portions 16 of the rotary table 12, respectively.

Subsequently, the shutter 18 is closed and the interior of theprocessing vessel 11 is vacuumed by a vacuum pump (no(shown) connectedto the exhaust port 26. The N₂ gas as the separation gas is dischargedfrom the separation gas nozzles 22 and 24 at a predetermined flow rateand supplied into the space 28 in the central region C of the rotarytable 12 at the predetermined flow rate. Thus, an internal pressure ofthe processing vessel 11 is adjusted to a preset pressure by a pressureadjustment part (not shown) connected to the exhaust port 26.

Thereafter, the product wafers are heated to, for example, 400 degreesC., by the heater 20 while rotating the rotary table 12 clockwise. TheBTBAS gas is supplied from the first reaction gas nozzle 21, and the O₃gas is supplied from the second reaction gas nozzle 23.

When the product wafer passes through the first processing region P1,the BTBAS gas as a raw material gas is supplied from the first reactiongas nozzle 21 to be adsorbed onto a surface of the product wafer. Theproduct wafer having the BTBAS gas adsorbed onto the surface thereof ispurged by passing through the separation region D1 in which theseparation gas nozzle 22 is installed, with the rotation of the rotarytable 12, and subsequently, enters into the second processing region P2.

In the second processing region P2, the O₃ gas is supplied from thesecond reaction gas nozzle 23, so that a Si component contained in theBTBAS gas is oxidized by the O₃ gas. Thus, an SiO₂ as a reaction productis deposited on the surface of the product wafer. The product waferpassed through the second processing region P2 is purged by passingthrough the separation region D2 in which the separation gas nozzle 24is installed, and subsequently, re-enters into the first processingregion P1.

Further, the BTBAS gas is supplied from the first reaction gas nozzle 21to be adsorbed onto the surface of the product wafer.

In this way, by continuously rotating the rotary table 12 a plurality oftimes, the BTBAS gas and the O₃ gas are supplied into the processingvessel 11. Thus, the SiO₂ as the reaction product is deposited on thesurface of the product wafer, thereby forming a SiO₂ film (silicon oxidefilm).

Here, during the film forming process for the product wafer,temperatures of the zone heating heaters 20 a, 20 b, and 20 c aremeasured by the heater thermocouples 3 a, 3 b, and 3 c corresponding tothe zones Za, Zb, and Zc, respectively. The measurement values areinputted to the temperature control part 5. In addition, the temperaturecontrol part 5 drives the heater driving part 6 to control each of thezone heating heaters 20 a, 20 b, and 20 c, based on the measuredmeasurement values and the table stored in the medium 7 which will bedescribed later.

The film forming process for the product wafer is performed as describedabove. In this embodiment, prior to the aforementioned film formingprocess for the product wafer, a correlation between the measurementvalues measured by the heater thermocouple 3 and the measurement valuesmeasured by the radiation temperature measuring part 4 is tabulatedusing a dummy wafer (e.g., a SiC wafer). In the film forming process forthe product wafer, the temperature control is performed with referenceto the table.

First, by the same method as the film forming process for the productwafer, dummy wafers are mounted in the five concave portions 16 of therotary table 12, respectively, and subsequently, the internal pressureof the processing vessel 11 is adjusted to a preset pressure.Thereafter, the dummy wafers are heated to, for example, 400 degrees C.,by the heater 20 while rotating the rotary table 12 clockwise.

Subsequently, the temperatures of the zone heating heaters 20 a, 20 b,and 20 c are measured by the respective heater thermocouples 3 a, 3 b,and 3 c, and the temperatures of the dummy wafers are measured by theradiation temperature measuring part 4. In addition, a correlationbetween the measurement values measured by the heater thermocouples 3 a,3 b, and 3 c and the measurement values measured by the radiationtemperature measuring part 4 is tabulated by the temperature controlpart 5. In some embodiments, the temperatures of the respective heaterthermocouples 3 a, 3 b, and 3 c when the measurement value of theradiation temperature measuring part 4 becomes a temperature used in thefilm forming process may be tabulated us shown in FIG. 7. FIG. 7 is atable illustrating a correlation between the heater thermocouples 3 a, 3b, and 3 c and the radiation temperature measuring part 4.

Processing conditions applied when creating the table may be set equallyto those in the film forming process for the product wafer. Also, in acase where a plurality of temperature conditions is applied in the filmforming process for the product wafer, a plurality of tables may beprepared in advance by changing the temperatures measured by theradiation temperature measuring part 4 to meet the plurality oftemperature conditions in the film forming process for the productwater. Accordingly, even if the plurality of temperature conditions isapplied in the film forming process for the product wafer, the heatingpart can be controlled with reference to the respective tablecorresponding to the temperature conditions in the film forming processfor the product wafer, which makes it possible to accurately control atemperature of a substrate.

Also, even if temperature conditions in the film forming process for theproduct wafer are not determined or even if the temperature conditionsare likely to be changed, a plurality of tables listed up at apredetermined interval of temperature (e.g., 10 degrees C.) may beprepared in advance such that the temperature of the substrate can beaccurately controlled. Thus, even if any temperature conditions in thefilm forming process for the product wafer are not determined or even ifsuch temperature conditions have been changed, the heating part can becontrolled with reference to the temperature conditions in the filmforming process for the product wafer or a respective table close to thetemperature conditions in the film forming process for the productwafer. This makes it possible to accurately control the temperature ofthe substrate.

Meanwhile, the temperature measurement by the radiation temperaturemeasuring part 4 is performed while rotating the rotary table 12. Assuch, a temperature (e.g., a temperature of the rotary table 12) otherthan the temperature of the dummy wafer is sometimes included in themeasurement value.

Therefore, it is preferably for the temperature control part 5 todetermine whether the measurement value measured by the radiationtemperature measuring part 4 to be inputted to the temperature controlpart 5 is the temperature of the dummy wafer.

The determination method performed by the temperature control part 5 isnot particularly limited. As an example, the temperature control part 5determines whether the measurement value inputted from the radiationtemperature measuring part 4 is the temperature of the dummy wafer,based on signals related to a rotational position and a rotational speedof the rotary table 12, which are inputted from the rotary drivemechanism 12 a. Specifically, the determination is performed bycomparing information on preset rotational positions of the five concaveportions 16 of the rotary table 12 with information on the rotationalposition and the rotational speed of the rotary table 12.

Upon completing the creation of the table in this way, theaforementioned film forming process for the product wafers is performed.The film forming process for the product wafers is repeated, forexample, until maintenance work such as exchange of parts of the heattreatment apparatus 1 is needed. After the maintenance work of the heattreatment apparatus 1 is performed, the creation of a table is resumed.A timing at which the creation of the table is performed is not limitedto after the maintenance work of the heat treatment apparatus. In someembodiments, the creation of the table may be performed at anothertiming, for example, after a cleaning process is performed, and thelike.

Next, a temperature of the wafer W mounted on the rotary table 12 willbe described.

First, examples of temperature distributions of the wafers W (the rotarytable 12) in a state where the rotary table 12 is being rotated and in astate where the rotary table 12 is not being rotated will be described.FIGS. 8A and 8B are views illustrating temperature distributions of thewafer in the state where the rotary table 12 is being rotated and in thestate where the rotary table 12 is not being rotated. Specifically, FIG.8A shows a temperature distribution of the wafer W (the rotary table 12)when the heater 20 is controlled such that the temperature of the waferW becomes 760 degrees C. in the state where the rotary table 12 is beingrotated. FIG. 8B shows a temperature distribution of the wafer W (therotary table 12) when the heater 20 is controlled such that thetemperature of the wafer W becomes 760 degrees C. in the state where therotary table 12 is not being rotated.

As shown in FIGS. 8A and 8B, it can be seen that the temperaturedistribution of the wafer W (the rotary table 12) in the state where therotary table 12 is being rotated is considerably different from that inthe state where the rotary table 12 is not being rotated. From this, itcan be known that it is important to accurately measure a temperature ofa wafer in a film forming process performed in the state where therotary table 12 is being rotated.

Next, temperatures of the wafers W when the heater 20 is controlled bythe aforementioned temperature control method will be described.

FIG. 9 is a view illustrating positions of the wafers W mounted on therotary table 12. FIGS. 10A and 10B are views illustrating an effect ofthe heat treatment apparatus 1 according to the embodiment of thepresent disclosure.

Specifically, FIGS. 10A and 10B are graphs showing results obtained bymeasuring, by the radiation temperature measuring part 4, temperaturesof the wafer W (the rotary table 12) when rotating the rotary table 12clockwise by 360 degrees along an arrow A in FIG. 9. FIG. 10A is a graphwhen the heater 20 is controlled by the aforementioned temperaturecontrol method, and FIG. 10B is a graph when the heater 20 is notcontrolled by the aforementioned temperature control method. In each ofFIGS. 10A and 10B, a horizontal axis represents a position and avertical axis represents a temperature.

In each of FIGS. 10A and 10B, a solid line, a dashed line, and a dottedline represent temperatures of the wafer W (the rotary table 12) in thezone Za (indicated by an arrow Aa), the zone Zb (indicated by an arrowAb), and the zone Zc (indicated by an arrow Ac) when rotating the rotarytable 12 along the arrow A of FIG. 9, respectively. As shown in FIGS.10A and 10B, the temperature in each of the zones Za, Zb, and Zcripples. This is because the wafer W and the rotary table 12 arealternately measured.

As shown in FIG. 10A, it can be seen that when the heater 20 iscontrolled by the aforementioned temperature control method, thetemperatures of the wafer W in all of the zones Za, Zb, and Zc are thesame as a target temperature (a temperature in the film formingprocess).

On the other hand, as shown in FIG. 10B, it can be seen that when theheater 20 is controlled without having to use the aforementionedtemperature control method (without having to use the aforementionedtable), the temperatures of the wafer W in all of the zones Za, Zb, andZc are considerably deviated from the target temperature. Specifically,the temperatures of the wafer W in the zones Za and Zc are higher thanthe target temperature, and the temperature of the wafer W in the zoneZb is lower than the target temperature. Therefore, it can be seen thata variation in the temperature of the water W in the diameter directionof the rotary table 12 increases.

As described above, according to the heat treatment apparatus and thetemperature control method of the embodiment, the temperature of thewafer W is measured by the radiation temperature measuring part 4. Thismakes it possible to measure the temperature of the wafer W with a highdegree of accuracy. Furthermore, the temperature of the heater 20 ismeasured by the heater thermocouple 3 and the temperature control part 5controls the heater 20 based on the temperatures measured by the heaterthermocouple 3 and the temperature measured by the radiation temperaturemeasuring part 4 so that the temperature of the wafer W is controlled.It is therefore possible to accurately measure the temperature of thewafer W.

Although in the above embodiments, the heat treatment apparatus and thetemperature control method have been described, the present disclosureis not limited thereto and various changes and modifications may be madewithin the scope of the present disclosure.

Although in the above embodiments, the radiation temperature measuringpart 4 has been described to be used as the second temperature measuringmeans, the present disclosure is not limited thereto. A non-contact typetemperature measuring means may be used as the second temperaturemeasurement means. As an example, a radiation thermometer or a wirelesstemperature sensor using surface acoustic waves may be used as thesecond temperature measurement means.

According to the present disclosure in some embodiments, it is possibleto provide a heat treatment apparatus which includes a rotary tablehaving substrates mounted thereon and rotating inside a processingvessel, and can accurately control temperatures of the substrates.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosures. Indeed, the embodiments described herein maybe embodied in a variety of other forms. Furthermore, various omissions,substitutions and changes in the form of the embodiments describedherein may be made without departing from the spirit of the disclosures.The accompanying claims and their equivalents are intended to cover suchforms or modifications as would fall within the scope and spirit of thedisclosures.

What is claimed is:
 1. A heat treatment apparatus for performing apredetermined film forming process on a substrate by mounting a set of aplurality of substrates on a surface of a rotary table installed in aprocessing vessel and heating the plurality of substrates by a heatingpart while rotating the rotary table, the heat treatment apparatuscomprising: a contact type thermocouple configured to measure atemperature of the heating part; a non-contact type radiationtemperature measuring part configured to measure a temperature of thesubstrate mounted on the rotary table in a state where the rotary tableis being rotated; and a temperature controller configured to control thethermocouple and the radiation temperature measuring part to perform aprocess including: prior to performing the predetermined film formingprocess, mounting a set of a plurality of dummy substrates on the rotarytable, tabulating a correlation between a first measurement valuemeasured by the thermocouple and a second measurement value measured bythe radiation temperature measuring part using the set of the pluralityof dummy substrates, and storing the tabulated correlation into astorage part; determining whether the second measurement value is thetemperature of the dummy substrates; and after storing the tabulatedcorrelation, performing the predetermined film forming process onadditional sets of the plurality of the substrates while controlling theheating part based on the correlation stored in the storage part,wherein the thermocouple and the radiation temperature measuring partmeasure temperatures in a plurality of regions defined along a diameterdirection of the rotary table.
 2. The heat treatment apparatus of claim1, wherein the temperature controller controls the heating part suchthat the temperature measured by the radiation temperature measuringpart meets a temperature condition applied when performing thepredetermined film forming process, and subsequently, tabulates thecorrelation between the first measurement value and the secondmeasurement value, and stores the tabulated correlation into the storagepart.
 3. The heat treatment apparatus of claim 1, wherein thetemperature controller changes the temperature measured by the radiationtemperature measuring part to meet a plurality of temperature conditionsapplied when performing the predetermined film forming process,tabulates the correlation between the first measurement value and thesecond measurement value under each of the plurality of temperatureconditions, and stores the tabulated correlation into the storage part.4. The heat treatment apparatus of claim 1, wherein the radiationtemperature measuring part detects an infrared ray radiated from asurface of the substrate to measure the temperature of the substrate.